TWI661222B - Optical measuring device and optical measuring method - Google Patents

Abstract

The present invention provides an optical measuring device for performing an optical measuring method for measuring an object to be measured. The optical measuring device includes a light source, a scanning device, and a photosensitive device. Light emitted by the light source is irradiated on the surface of the object to be measured through the scanning device. The light receiving device receives the light leaving the surface of the object to be tested. During the period when the light receiving device receives the light leaving the surface of the object to be tested, the scanning device moves the light on the surface of the object to be tested, which can avoid a single point on the surface of the object to be measured. The phenomenon of phototoxicity or photobleaching caused by excessive light irradiation improves the stability of the test object and the accuracy of the measurement result.

Description

Optical measuring device and method

The invention relates to an optical measuring device and an optical measuring method, which can be used to measure the optical properties of an object to be measured and can form a microscopic image after repeated measurements.

Microscopes can assist researchers or engineers to observe various materials and their structures from a microscopic scale. They are extremely important research tools for materials science, nanotechnology and biotechnology. Among them, the laser conjugate focal microscope developed recently is even more important. An important enabler of cutting-edge technology today.

The laser conjugate focus microscope is to place the test object at the focal point of the optical system, and irradiate the laser light to the test object. After the light spot of the laser light is reflected by the test object, it will be imaged at the other focal point of the optical system The pinhole set at the other focal point can filter out the reflected or diffused light reflected from other positions than the light point, and then collect and analyze the light passing through the pinhole with a spectrometer to measure the light point. The reflected light of the object to be measured is then combined with point-by-point and layer-by-layer measurement methods to further combine the measured data into a three-dimensional stereoscopic microscopic image of the object.

However, in the process of establishing the microscopic image of the test object, the test object is often deteriorated by the influence of laser light, and phototoxicity or photo bleaching occurs. Once the test object is photobleached, Will change the reflected light properties of the laser light after the object under test is reflected, which may affect the correctness of the pixel image at that point or adjacent pixels, and also affect the same The correctness of the images at different depths of the position limits the acquisition and use of microscopic images.

One object of the present invention is to provide an optical measuring device or an optical measuring method, which can reduce or avoid the phenomenon of phototoxicity or photobleaching during the process of obtaining microscopic images.

In order to achieve the above and other objectives, the present invention provides an optical measuring device including a light source, a scanning device, and a photosensitive device. The light source can emit an active light, and the scanning device can receive the active light and direct it toward a test object. The surface is irradiated, the active light is irradiated toward the surface to be measured and a light spot is formed on the surface to be measured. When the active light is irradiated toward the surface to be measured, the light point emits a passive light, and the scanning device can change the active light. The optical axis moves the light spot between at least two measured positions on the surface to be measured, the photosensitive device receives the passive light in an integration time, the photosensitive device outputs an output signal after receiving the passive light, and The light spot moves during the integration time and passes at least the two measured positions.

In order to achieve the above and other objectives, the present invention also provides an optical measurement method, which uses a scanning device to guide an active light emitted from a light source toward a surface to be measured, and forms a light spot on the surface to be measured, and A passive light exits from the light spot, the scanning device is operated to change the optical axis of the active light to move the position of the light spot between at least two measured positions, and a light receiving device is used to receive the light spot in an integration time Passive light leaving the light spot when passing through at least the two measured positions and outputting an output signal.

In some cases, the time during which the light spot is located in each measured position in the plane to be measured in the integration time is not more than one millisecond.

In some cases, the position of the light spot in the integration surface during the integration time Keep moving.

In some cases, the light source is a point light source, and an optical system is disposed between the light source and the scanning device, and the optical system can receive the active light and focus it on the surface to be measured.

With this, the optical measuring device provided by the present invention can be used to measure the optical properties of the object to be measured. When the object to be measured is placed on the surface to be measured, a light spot can be formed on the surface of the object to be measured, and the light spot is collected by the photosensitive device and left. The passive light is measured. In the integration time of the photosensitive device, the active light irradiation position or the position of the light spot can be moved, which can prevent the active light from shining on the same position of the object to be measured for a long time. The light receiving time and light energy of any single point on the surface or the point to be measured are greatly reduced, thereby avoiding or reducing the chance of phototoxicity or photobleaching of the object to be measured.

10‧‧‧ light source

11‧‧‧ Active Light

12‧‧‧ Passive Light

13‧‧‧light spot

20‧‧‧scanning device

21‧‧‧The first scanning mirror

22‧‧‧Second Scanning Mirror

23‧‧‧ Third Scanning Mirror

30‧‧‧ Photosensitive device

40‧‧‧ Optical System

41‧‧‧Optical Module

411‧‧‧shield

412‧‧‧Mirror

413‧‧‧ convex lens

414‧‧‧ Beamsplitter

42‧‧‧ Objective Lens Module

50‧‧‧treatment system

90‧‧‧DUT

91‧‧‧ surface to be tested

92, 93‧‧‧Tested position

94‧‧‧ range of movement

95‧‧‧moving path

FIG. 1 is a schematic diagram of a system of an optical measuring device according to the present invention.

FIG. 2 is a schematic diagram of a test surface of the optical measuring device of the present invention.

FIG. 3 is a schematic diagram of a scanning device in the optical measuring device of the present invention.

FIG. 4 is a schematic diagram of a measurement state of the optical measuring device of the present invention.

FIG. 5 is a schematic diagram of another measurement state of the optical measuring device of the present invention.

Please refer to FIG. 1. This embodiment provides an optical measuring device, which includes a light source 10, a scanning device 20 and a photosensitive device 30, and may further include an optical system 40 and a processing system 50 for measuring an object to be measured. 90 to obtain optical properties or images of the object to be measured 90. The optical measuring device of this embodiment measures toward a measurement surface 91. When measuring the measurement object 90, The test object 90 is placed on the test surface 91. The test surface 91 may specifically be an imaginary surface or a test object stage, or it may be a surface of glass or similar transparent material to place the test object 90 and Close to it.

The light source 10 can emit an active light 11 to illuminate the test object 90, make the test object 90 reflect light, transmit light, or excite fluorescent or scattered light, and emit passive light 12 from the test object 90. In this embodiment, In the measurement, the light reflected by the object to be measured 90 is used for measurement, and the passive light 12 is the reflected light of the object to be measured 90. Preferably, the light source 10 is a point light source. The light source 10 is, for example, a laser light source. Laser light sources of different wavelengths can be selected according to the type of the object to be measured 90 and the measurement purpose.

The scanning device 20 is, for example, an optical image scanning component described in TW I563288 patent. It is located in the optical axis of the active light 11 and can receive the active light 11 emitted by the light source 10 and illuminate it toward the surface to be measured 91, as described in Section 2. As shown in the figure, a light spot 13 is generated on the test surface 91. The light spot 13 is actually a light spot formed when the active light 11 and the test surface 91 meet or the active light is irradiated on the test object 90. When the test object 90 is placed, the test surface 91 may be only an imaginary surface, and no substance can reflect the active light 11 so that the light spot 13 cannot be seen by the naked eye. When the active light 11 is irradiated toward the test surface 91, the test object 90 placed on the test surface 91 can reflect the active light 11 to generate the passive light 12 and exit from the light spot 13. The scanning device 20 can change the active light 11 and the passive The optical axis of the light beam 12 moves the light spot 13 between any two or more measured positions on the surface to be measured 91. In more detail, please refer to FIGS. 1 to 3. The scanning device 20 may include a first scanning mirror 21 and a second scanning mirror 22. The first scanning mirror 21 may be a micro-electromechanical element, such as a resonant mirror. The element may be a rotating polygon mirror. The first scanning mirror 21 rotates around a first direction at a first resonance frequency. The second scanning mirror 22 is, for example, a galvano mirror unit. The two scanning mirrors 22 rotate around a second direction as an axis with a second resonance frequency, and the first direction is different from the second direction. Similarly, preferably, the first direction and the second direction are perpendicular to each other. For example, the first direction is the z-axis direction and the second direction is the x-axis direction. The light spot can be controlled in the test surface 91 by the first scanning mirror 21. Position of the x-axis and control of the y-axis position of the light spot on the surface to be measured 91 by the second scanning mirror 22, the first resonance frequency is, for example, 311 Hz, the second resonance frequency is, for example, 191 Hz, and the first scanning mirror 21 The active light 11 is reflected toward the second scanning mirror 22, so that the active light 11 is directly irradiated on the second scanning mirror 22 or reflected to the second scanning mirror 22 via another third scanning mirror 23, and the second scanning mirror 22 reflects the active light 11 is reflected toward the test surface 91, so that the active light 11 is irradiated toward the test surface 91. The rotation of the first scanning mirror 21 and the second scanning mirror 22 will reflect the active light 11 at different angles, and change the active light 11 Position and angle of the optical axis, thereby changing the position of the light spot 13 in the test surface 91; when the first scanning mirror 21 and the second scanning mirror 22 continue to rotate, the light point 13 will be along the non-test surface 91 Continuous movement in one direction. It should be noted that FIG. 3 is only for illustrative use, and the surface to be measured 91 is shown next to the second scanning mirror 22. In this embodiment, as shown in FIG. 1, the second scanning mirror 22 and the There is still another objective lens module 42 between the measurement surfaces 91, so as to focus the active light 11 on the measurement surface 91.

The photosensitive device 30 is, for example, a spectrometer, and a pinhole plate can be arranged in front of the photosensitive device 30, which can receive the passive light 12 through the pinholes of the pinhole plate, and can receive the passive light 12 during an integration time, and then according to the received The passive light 12 outputs an output signal. The photosensitive device can be controlled to adjust the length of the integration time. For example, the length of the integration time can be 10 ms, 1 ms, or less than 1 ms. During the integration time, the light spot 13 will be at The movement between at least two adjacent positions of the surface to be measured 91 is, for example, moving within a designated area of 10 micrometers square or any designated or unspecified area. In other words, during each integration time, The time at which any of the positions in the test surface 91 is irradiated by the active light 11 may be less than 1 millisecond. Preferably, the light spot 13 moves between two test positions that are far away from each other, and passes through several test positions. , Or at a specified Movement in the area, for example, please refer to Figure 4. If the integration time is 1 millisecond, both the first resonance frequency and the second resonance frequency are 2K Hz, and the inverse of the integration time is 0.1K. The ratio of the second resonance frequency to the reciprocal of the integration time is 2. The light spot 13 will move past the two measured positions 92 and 93, and move back and forth 4 times. By controlling the first resonance frequency, the second resonance frequency and the integration time The relative relationship between them can determine the measured position where the light spot 13 moves on the test surface 91 during the integration time.

Please refer to FIG. 1. The optical system 40 includes an optical module 41 and an objective lens module 42. The optical module 41 includes a light shielding plate 411 (shutter), two reflecting mirrors 412, a convex lens 413, and a beam splitter 414. The light shielding plate 411 is available. In order to control whether the active light 11 can be incident, the opening and closing of the light shielding plate 411 can be controlled by an electrical signal. When the light shielding plate 411 is turned on, the active light 11 will pass through the light shielding plate 411, the reflector 412, the convex lens 413, and the beam splitter 414. The active light 11 can be reflected and guided to the scanning device 20. When the light shielding plate 411 is closed, the active light 11 is blocked by the light shielding plate 411. The optical module 41 is disposed between the light source 10 and the scanning device 20, and the objective lens module 42 is disposed between the scanning device 20 and the surface to be measured 91. The focal points on both sides of the optical module 41 are respectively located on the surface to be measured 91 and the photosensitive device. 30, so that the active light can be focused on the surface to be measured, and the light spot can be imaged on the pinhole plate or the photosensitive device 30.

Please refer to FIG. 5. In a possible embodiment of the present invention, the first scanning mirror and the second scanning mirror can be controlled to reciprocate and rotate between respective specified angles, so as to control the light spot 13 in the test surface 91. The moving range 94 and the moving path 95 are used to perform point-by-point or area-by-area measurement using a value measured by the moving range 94 as a set of data or a set of pixels in one measurement. In this embodiment, the size of the moving range is, for example, 10 micrometers square.

The processing system 50 is connected to the photosensitive device 30 and can receive output signals from the photosensitive device 30 The output signal is further processed, and the output signal is combined into a microscopic image by means of point-by-point measurement and recording.

With the above device, when the user wants to perform optical measurement to obtain the microscopic image or optical property of the object to be measured, the user can activate the light source 10 and the scanning device 20 in succession, and place the object to be measured 90 on the surface to be measured 91 and scan. The device 20 can direct the active light 11 emitted from the light source 10 toward the surface to be measured 91 to illuminate, and a light spot appears on the surface to be measured 91 or the object to be measured 90, and the light spot is between the two measured positions or selected. Moving within the measurement range, the active light 11 is reflected by the object to be measured 90 at the light spot, and the passive light 12 is reflected by the light spot, and then the passive device 12 receives the passive light 12 and generates an output signal to process the system 50. Receive the output signal and perform signal processing or image processing to obtain the microscopic image or optical property to be measured by the user.

During the aforementioned measurement, the position of the active light 11 on the surface of the object to be measured is changed and moved by the scanning device 20. In the integration time of the photosensitive device, the position of the light spot will be in a line segment or a specified area It can move around without irradiating a single point, which can avoid or reduce the phenomenon that a single point of the object under test is continuously exposed to active light, causing phototoxicity or photobleaching. It can reduce the impact of the nature of the object during the measurement process and maintain The constant property of the test object helps to obtain stable and accurate measurement results.

In the above embodiment, the optical measuring device is essentially a conjugate focal microscope device. The active light is focused on the surface to be measured by the optical system, and the passive light reflected from the surface to be measured is focused and imaged on the photosensitive device or photosensitive device. The pinhole in the front, however, if the optical axis of the active light is bypassed or omitted, only the optical axis of the active light is guided by the scanning device, or the photosensitive device is collected by the active light to be excited by the test object. Fluorescence or scattered Raman light, further changing the optical measuring device to other types of microscopy devices, such as total internal angle reflection fluorescence microscopy Mirror is also possible.

Summarizing the above description, the optical measuring device of the above embodiment can reduce the chance of phototoxicity and photobleaching of the test object, improve the stability of the sample property of the test object, and obtain stable and accurate measurement results. It is indeed academia and industry It is expected that the above embodiments are only for explaining and explaining the technical content of the present invention, and the patent scope of the present invention shall be subject to the scope of patent application of the present invention.

Claims (10)

An optical measuring device includes: a light source capable of emitting an active light; a scanning device capable of receiving the active light and irradiating the active light toward a surface to be measured, and the active light being radiated toward the surface to be measured to make the A light spot is generated on the test surface, and a passive light beam is emitted from the light spot when the active light is illuminated toward the test surface. The scanning device can change the optical axis of the active light to make the light spot on the test surface. At least two measured positions move in a non-single direction; a photosensitive device can receive the passive light, the photosensitive device receives the passive light in an integration time, and the photosensitive device outputs an output signal after receiving the passive light; , The light spot moves during the integration time and passes at least the two measured positions. The optical measuring device according to item 1 of the scope of patent application, wherein in the integration time, the time that the light spot is positioned at each measured position in the surface to be measured is not more than one millisecond. The optical measuring device according to item 1 of the scope of patent application, wherein during the integration time, the light spot continuously moves in a specified area of the surface to be measured or continuously between two measured positions. Move back and forth. The optical measuring device according to item 1 of the patent application range, wherein the light spot continuously moves in a specified area of the surface to be measured, and the photosensitive device receives the passive from the specified area in the integration time. Light, and output a set of pixels according to the passive light. The optical measuring device according to any one of claims 1 to 4, further comprising an optical system, the light source is a point light source, and the optical system is disposed between the light source and the surface to be measured. The system can receive the active light and focus it on the test surface. An optical measurement method is to use an scanning device to guide an active light emitted from a light source toward a surface to be measured, so that the surface to be measured shows a light spot, and the light spot emits a passive light. The scanning device Changing the optical axis of the active ray so that the position of the light spot moves in a non-single direction between at least two measured positions, and a photosensitive device is used to receive the light spot moving past the at least two measured positions in an integration time The passive light is emitted and an output signal is output. The optical measurement method according to item 6 of the scope of patent application, wherein in the integration time, the time that the light spot is positioned at each measured position in the surface to be measured is not more than one millisecond. The optical measurement method according to item 6 of the scope of patent application, wherein during the integration time, the light spot continuously moves in a specified area of the surface to be measured or continuously between two measured positions. Move back and forth. The optical measurement method according to item 6 of the scope of patent application, wherein the light spot continuously moves in a specified area of the surface to be measured, and the photosensitive device receives the passive from the specified area in the integration time. Light, and output a set of pixels according to the passive light. The optical measurement method according to any one of claims 6 to 9, wherein the light source is a point light source, and an optical system is arranged between the light source and the surface to be measured, and the optical system can receive the light source And focus it on the surface to be measured.